You specify a parameter by passing one (or more) com::sun::star::beans::PropertyValue object(s) to the initialize method, where the Name field contains a string describing which aspect you want to affect, and the Value field containing a value.
Imagine the initialization values as if you use setPropertyValue of the com::sun::star::beans::XPropertySet interface ...
allowed parameters are

Title
String describing the initial title of the dialog. If not specified, a default title is used.